"The Google Cast extension is available on all platforms, including Chrome OS, Windows, Mac OS X, and Linux. There are no specific hardware requirements in order to install or use the Google Cast extension.

However, casting video from a tab of your Chrome Browser has specific requirements depending on your chosen quality settings. Systems that do not meet these minimum requirements will be limited to projecting web pages, images and slideshows, and will not work well for video content. A strong Wi-Fi connection both on Chromecast and your computer is also required for good performance. "

No, I afraid not. I know that it isn’t exactly the same thing, but you could use Miracast as a substitute. I would be surprised if RT support is ever added to Chromecast, in light of its relatively low adoption rate.